Adjustable time timing gear for timing apparatus

ABSTRACT

A driving gear is adjustable along the longitudinal axis of its supporting shaft to a plurality of positions. The gear has different numbers of teeth at the various positions so that positioning of the cam on its shaft determines the gear ratio between the driving gear and a driven gear.

United States Patent [191 Christianson Jan. 21, 1975 ADJUSTABLE TIMETIMING GEAR FOR TIMING APPARATUS [75] Inventor: Robert W. Christianson,St. Joseph,

Mich.

[73] Assignee: Whirlpool Corporation, Benton Harbor, Mich.

22 Filed: May 29,1973

[21] Appl. N0.: 364,732

[52] U.S. Cl. 74/568 T, 74/3.5, 74/435 [51] Int. Cl. Fl6h 53/00 [58]Field of Search 74/3.5, 325, 352, 431,

74/432, 434, 435, 337, 421, 568 T, 460, 468, 640; 200/38 A, 38 R, 35 R;58/7, 8, 23 D, 28

[56] References Cited UNITED STATES PATENTS 2,874,809 2/1959 Poole74/435 X Hall 74/568 T Cartier 74/568 T Primary Examiner-Benjamin W.Wyche Assistant ExaminerFrank H. McKenzie, Jr. Attorney, Agent, orFirm-Hill, Gross, Simpson, Van Santen, Steadman & Chiara [5 7] ABSTRACTA driving gear is adjustable along the longitudinal axis of itssupporting shaft to a plurality of positions. Thegear has differentnumbers of teeth at the various positions so that positioning of the camon its shaft determines the gear ratio between the driving gear and adriven gear.

15 Claims, 5 Drawing Figures ADJUSTABLE TIME TIMING GEAR FOR TIMINGAPPARATUS BACKGROUND OF THE INVENTION 1. Field of the Invention Thepresent invention relates to. an adjustable time timing gear, and moreparticularly to a timing gear carried on a supporting shaft and havingmeans for releasably locking the gear at selected positionslongitudinally of the supporting shaft.

2. Description of the Prior Art It is well known in the art to providedifferent gear ratios between a driving gear and a driven gear bychanging the number of teeth presented by one gear to the other. Forexample, U.S. Pat. No. 2,328,473 discloses a traffic signal controlleror timer which employs a pinion for driving a selected gear of a conegear. The desired gear ratio is obtained by pivoting the pinion todisengage from the cone gear, sliding the pinion and its prime moverlongitudinally of the cone gear on a sepa rate shaft parallel theretoand then pivoting the pinion to again engage the cone gear. U.S. Pat.No. 2,907,221 discloses the use of a cone gear as the driving gear forselective engagement with a pinion as the driven gear. Selectiveengagement at different gear ratios is provided by means of a cam andlever arrangement which positions the pinion longitudinally of the conegear. Each of the foregoing types of apparatus for providing differentgear ratios involves the provision and use of additional levers, shaftsand/or cam mechanisms for positioning one of the gears with respect tothe other, both longitudinally of the axis of one of the gears andradially with respect to the axis of the cone gear due to the steppedconfiguration of a cone gear.

U.S. Pat. No. 3,075,055 discloses a control member which functions as atiming gear for driving a toothed wheel at different rates. The controlmember has a plurality of spaced teeth about the circumference thereof,which teeth are radially displaceable for selective engagement with orbypassing of the teeth of the driven toothed wheel. The movable teethmay therefore be radially displaced in selected patterns to provide thevarious rates of revolution of the toothed wheel. Although thisstructure eliminates the aforementioned disadvantage of moving one gearradially with respect to the other, the provision of additional parts inthe form of movable teeth is in itself a disadvantage.

SUMMARY OF THE INVENTION It is an object of the present invention toprovide a timing gear arrangement which is easily adjustable to providea plurality of gear ratios between a driving gear and a driven gear.

Another object of the invention is to provide an adjustable time timinggear arrangement in which the selection of gear ratios is accomplishedby movement of one gear with respect to the other only in thelongitudinal direction of its axis.

Another object of the invention is to provide a longitudinallyadjustable gear having different numbers of teeth at different positionsalong its axis which teeth have the same mean diameter.

Another object of the invention is to provide a simple means forreleasably engaging the adjustable gear at different positionslongitudinally of its supporting shaft.

Another object of the invention is to eliminate the great number ofpiece parts which were necessary in prior arrangements for providingdifferent gear ratios and to provide an adjustable timing gear which isselectively and releasably engaged at positions along its supportingshaft, wherein the gear, the shaft and the means for releasably engagingthe gear and the shaft are provided by only two piece parts.

A gear is provided with a plurality of gear sections at differentpositions along its longitudinal axis. At these positions the gear hasdifferent numbers of teeth, all of which have the same mean diameter sothat longitudinal movement of the gear, parallel to the axis of rotationof the gear mated therewith, changes the gear ratio. The gear is moldedfrom a plastic material as a single piece part. By the same token, thesupporting shaft for the gear is molded of plastic material and includesa plurality of resilient locking tabs for releasably engaging the gearat the different gear ratio locations.

BRIEF DESCRIPTION OF THE DRAWINGS Other objects, features and advantagesof the invention, its organization, construction and operation will bebest understood from the following detailed description of a preferredembodiment thereof, taken in conjunction with the accompanying drawings,on which:

FIG. 1 is a pictorial view, shown partially broken away, of acoin-operated clothes dryer as an exemplary environment for a timeremploying the present invention;

FIG. 2 is an end view of a timer constructed in accordance with theprinciples of the present invention;

FIG. 3 is a view similar to FIG. 2 showing the timer in an operatingcondition;

FIG. 4 is a pictorial representation of apparatus constructed inaccordance with the present invention; and

FIG. 5 is a sectional view taken generally along the line V-V of FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodiment of theinvention is illustrated in FIG. 1 in the environment of a commercialclothes drying appliance 10 which comprises an enclosure cabinet 12having a console 14 thereon. The console 14 comprises a coin box 17having a slide-type coin slot device 18, and houses a timing device 16for regulating the drying operation. The enclosure cabinet 12 furthercomprises horizontal top and bottom panels 20 and 22, respectively, apair of vertical side panels 24, only one of which can be seen on thedrawing, and vertical front and rear panels 26 and 28, respectively. Theenclosure cabinet 12 further comprises an access opening 30 in the frontpanel 26, as defined by an inturned flange 31. The access opening 30 hasa closure door 32 cooperating therewith for loading and unloading thedryer 10.

The dryer 10 further includes a drying container for tumbling clothes inthe form of a revolving drum 34 housed within the cabinet 12 andextending axially from the front panel 26 to a bulkhead 36 spacedforwardly of the rear panel 28. In order to promote a tumbling action ofthe clothing being dryed, a plurality of circumferentially spacedbaffles 78 (one being illustrated on the drawing) are mounted on theinner surface of the drum 34. The drum 34 includes a radially inwardextending front closure wall 41 having an access opening 42 thereinformed by means of an axially outturned flange 43. The flange 43provides a forwardly extending annular bearing which overlies and issuitably journaled on the complementary flange 31 of the enclosurecabinet 12. It will be apparent from the foregoing description that theopening 42 into the drum 34 and the opening 30 formed in the front panel26 are concentric, providing access into the rotatable drum 34 from theoutside of the cabinet 12. The drum 34 is supported at the rear by apair of support rollers 48 (one being illustrated on the drawing)mounted on the bulkhead 36. A raceway or circumferential groove 50,formed as a circumferential indentation in the peripheral wall of therear portion of the drum 34 serves as a track for the rollers 48.

The appliance also comprises a motor 52 mounted on the bottom panel 22in a rear corner of the cabinet 12 which rotatably drives the drum 34 bymeans of a drive belt 54 extending around the periphery of and infrictional engagement with the drum 34 and around a motor pulley 56mounted at one end of a motor shaft 58. The other end of the motor shaft58 is connected to drive a blower 60 which is arranged to circulate airthrough the drum 34. The blower 60 is included in a warm air system 62positioned between the rear panel 28 and the bulkhead 36.

The bulkhead 36 serves to enclose an open-ended rear portion of the drum34 and provides a fixed rear wall in which is located a pair of spacedopenings which are covered by respective perforate sections to providean air inlet 64 and an air outlet 66. The blower 60 draws moisture-ladenair from the interior of the drum 34 through the air outlet 66, througha removable lint screen 68, through an air duct 70 and exhausts the airout of the cabinet 12 through an exhaust duct 72. Air exhausted from thedrum 34 is replaced by ambient air entering the warm air system 62 byway of an intake opening in rear panel 28 (not shown) and passes over aheater means 76 as it is drawn through a fresh air duct 74 and into thedrum 34 through the air inlet 64. The warm air system 62 thus circulatesa stream of warm air through the drum 34, subjecting the clothing placedtherein to a drying environment to remove moisture from the fabricswhile the clothing is tumbled as the drum 34 rotates.

Referring to FIGS. 2 and 3, the timing device 16 of FIG. 1 isillustrated in greater detail. The timing device 16 has encasement wallmembers 90 and 91 which enclose the timing mechanism. A lever 100 isactuated through the movement of the coin slot device 18. When actuatedthe lever 100 rotates about a pin 92 and when released rotates under thebias caused by a spring 93 back to its original or returned position. Itshould here be noted that it is common practice in laundryestablishments to provide a certain amount of drying time in return fora certain denomination of coin inserted into the coin mechanism and toprovide multiples of such drying time for each multiple of suchdenomination, i.e., for each actuation of the lever 100. The lever 100acts through a ratchet wheel or one way clutch mechanism 101 to rotate aface cam 102 in the direction shown by the arrow when the lever isreleased to return to its original position. A face cam 103 is splinedthrough a pair of telescopically related spline collars 104, 106 to agear 105. The gear 105 is frictionally engaged by a detention springmember 110 so that rotation of the gear 105 is resisted. Therefore, whenthe face cam 102 is rotated by the lever 100, the cam 103 does not atfirst rotate, but is forced away from the cam 102 by the action of therespective camming surfaces 112 and 1 l 1 against the spring bias of apair of switches 115 and 116. The cams 102 and 103 move in oppositedirections axially of the shaft 92 in two steps, thereby first actuatingthe switch 115 and then actuating the switch 116. The switch 115actuates the drive motor 52 and a timing motor 117 and the switch 116actuates the heater 76. When the cam 103 has been rotated to theposition shown in FIG. 3, the two cams 102, 103 lock together by theaction of a locking surface 113 on the cam 102 on a locking surface 114on the cam 103. Any further rotation of the cam 102, as may be effectedby the insertion of additional coins and movement of the lever 100,causes both the cam 102 and the cam 103 to rotate together by overcomingthe friction of the spring on the gear 105. This further rotation of thecams also causes a pin 107 on the gear 105 to begin to separate from apin 109 on a star wheel 108. FIG. 2 illustrates the pins before rotationof the cam 103, while FIG. 3 shows the pins after rotation of the cam103. The timer 117 acts through a shaft 121 to rotate a timing gear 120to rotate the star wheel 108. After actuation of the timer motor 117 byswitch 115, the star wheel 108 will be rotated by timing gear 120 todrive the pin 109 until contact with the pin 107 is made. At this point,the star wheel 108 will begin to rotate the cam 103 with respect to thecam 102, the latter being held stationary by the ratchet mechanism 101when the lever 100 is in the returned position. Rotation of the cam 103with respect to the cam 102 will cause a time period to elapse and thenthe cams will move toward each other in two steps as the cam surface 112rotates back into contact with the cam surface 111. The first step willdeactivate the heater 76 by permitting the switch 116 to restore underthe influence of its spring bias, and the second step will deactivatethe drive motor 52 and the timer motor 117 by permitting restoration ofthe switch under the control of its bias. This sequence provides for acool down at the end of each cycle, regardless of how many coins areinserted to lengthen the drying time by arcuately separating the pins107 and 109.

Referring now to FIGS. 4 and 5, the timing gear 120 is illustrated ingreater detail. The gear 120 comprises a generally cylindrical memberhaving rounded teeth, the number of teeth varying along the longitudinalaxis of the gear. By positioning the gear 120 on a supporting shaft 121so that a given number of teeth will engage the star wheel 108, theamount of drying time to be provided for the number of coins insertedcan be selected in that the number of revolutions of the gear 120 perrevolution of the star wheel 108 can be selected.

The gear 120 is releasably locked into position on the shaft 121 by oneor more of a plurality of tabs 122, 123, 124, and 126, which extend atan acute angle with respect to the surface of the shaft 121, asillustrated in FIGS. 4 and 5. The shaft 121 and the tabs 122-126 aremolded as a single part, as is the gear 120. The shaft 121 is driven bythe timer motor 117 by way of a shaft 118. As shown on the drawing,there are five possible positions of the gear 120 on the shaft 121, inthis particular exemplary embodiment. The possible positions allow for8, 6, 12, 4 or 9 teeth to drivingly engage the teeth of the star wheel108. In FIGS. 4 and 5, the gear 120 is in the position for 12 teeth toengage the star wheel 108. This would provide, for example, fifteenminute timing increment for each actuation of lever 100. To provide a 45minute increment, the gear 120 is moved outwardly on the shaft to aposition for four teeth, by depressing the locking tab 124 and movingthe gear toward the locking tab 123. The tabs 122-126 are resilient sothat when the gear 120 is moved in the direction of the arrow shown onthe shaft 121, the tab 126 moves upwardly, as viewed in FIG. 5, so thatthe gear 120 is grasped between the tabs 124 and 126. To provide aminute increment, the cam is moved to the position for nine teeth bypressing the locking tab 123 and moving the gear 120 out to abut the tab122. The gear 120 will then be releasably locked between the tabs 122and 125.

To provide a 22 /2 minute increment, the gear 120 is moved to theposition for eight teeth by depressing the locking tab 122, removing thegear 120 from the shaft 121, reversing the ends of the gear 120 andplacing the gear back on the shaft until it is locked between the tabs122 and 125. To provide a 30 minute increment, the gear 120 is moved tothe position for six teeth by depressing the locking tab 125 and pushingthe timing cam in the direction opposite to that of the arrow until itis locked between the tabs 123 and 126. The gear 120 therefore providesfive variable time periods, in this particular embodiment, that can beselected for a timing mechanism to vary the gear ratio between the gear120 and the driven wheel, in this case the star wheel 108.

The simplicity in changing the gear ratio is readily apparent from theforegoing description and the associated figures of the drawing.Therefore, the owner, or maintenance personnel, of a commercial laundryestablishment can easily select gear ratios for the timing mechanism andis therefore provided with an additional degree of flexibility inrelating coins and drying times.

Although I have described my invention by reference to a particularillustrative embodiment thereof, many changes and modifications of theinvention may become apparent to those skilled in the art withoutdeparting from the spirit and scope of the invention. I therefore intendto include within the patent warranted hereon all such changes andmodifications as may reasonably and properly be included within thescope of my contribution to the art.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. In a timer apparatus of the type wherein a control mechanism iscoupled to be driven by a motor via a gear train including first andsecond meshed gears, the improvement therein of means for varying thegear ratio of said first and second gears to vary the rate at which saidmotor drives said control mechanism, wherein:

said first gear including at least two sections at positions along itsaxis of rotation, each section including a different number of teeth andthe teeth of each section providing the same mean diameter for saidfirst gear as the teeth in each other section; and

locking means for selectively and releasably locking one of said gearsat positions along its axis of rotation to selectively mesh the teeth ofsaid first gear with the teeth of said second gear at different gearratios.

2. The improvement in timer apparatus, as set forth in claim 1, whereinsaid first gear is mounted for rotation on a supporting shaft and saidlocking means includes a plurality of resilient tabs spaced along andextending from said supporting shaft for engaging a face of said firstgear when such face is positioned adjacent thereto.

3. The improvement in timer apparatus, as set forth in claim 2, whereinsaid shaft and said tabs are formed as a unitary structure.

4. The improvement in timer apparatus, as set forth in claim 2, whereinsaid tabs extend at an acute angle with respect to the surface of saidsupporting shaft.

5. The improvement in timer apparatus, as set forth in claim 4, whereina first group of said tabs are directed toward one end of saidsupporting shaft and a second group of said tabs are directed toward theother end of said supporting shaft so that said first gear may be lockedbetween a tab of said first group and a tab of said second group.

6. Timer apparatus comprising:

a motor;

a first shaft connected to and rotated by said motor;

a first gear carried on said first shaft for rotation therewith, saidfirst gear including sections axially thereof having different numbersof teeth,

said first gear having the same mean tooth diameter at all saidsections;

a second shaft mounted for rotation;

a control mechanism connected to said second shaft and operated by therotation thereof to perform at least one control operation;

a second gear having teeth engaged with teeth of said first gear andcarried on said second shaft for rotating said second shaft,

one of said gears fixed to its respective shaft and the other of saidgears being axially movable along its respective shaft; and

locking means for locking said axially movable gear at a selectedposition on its respective shaft for selecting the gear ratio betweensaid first and second gears and the rate of operation of said controlmechanism.

7. The apparatus according to claim 6, wherein said locking meansincludes spaced, resilient tabs extending from the shaft which carriesthe axially movable gear.

8. The apparatus according to claim 7, wherein said tabs and said shaftwhich carries the axially movable gear are constructed as a singleunitary structure.

9. The apparatus according to claim 7, wherein said tabs extend at anacute angle with respect to the surface of the shaft which carries theaxially movable gear.

10. The apparatus according to claim 7, wherein a first group of saidtabs extend at an acute angle from the surface of and are directedtoward one end of the shaft which carries the axially movable gear, asecond group of said tabs extend at an acute angle from the surface ofand are directed toward the other end of the shaft which supports theaxially movable gear, and the axially movable gear may be positioned andreleasably locked between a tab of said first group and a tab of saidsecond group.

11. For use in a coin-operated laundry appliance of the type having arotatable clothes receptacle, means for treating clothes within thereceptacle and a coinoperated timing device, said timing devicecomprising:

a rotatable shaft; means operable upon the insertion of coins of apredetermined denomination to rotate said shaft in a first direction;

a motor operable to rotate said shaft in the opposite direction;

means coupled to said shaft for controlling the operation of said meansfor treating clothes;

a gear train driven by said motor and connected to said shaft andincluding a first gear having a plurality of gear sections disposedalong its longitudinal axis, each of said sections including differentnumbers of teeth and all sections having the same mean tooth diameter,

a second gear having teeth engageable with the teeth of said first gear,and

means for providing relative longitudinal movement between said twogears and releasably and selectively locking said two gears with respectto said longitudinal movement to provide a selected gear ratiotherebetween.

12. In a dryer having a coin-operated control mechanism, said mechanismhaving a motor and means including a driven gear driven by said motorfor controlling timing operations of said dryer, an adjustable geardriven by said motor for varying the rate at which said motor drivessaid means for controlling the timing operations of said dryer, saidadjustable gear comprising:

an essentially cylindrical member, a first plurality of teethcircumferentially protruding from said member, a second plurality ofteeth circumferentially protruding from said member, said secondplurality of teeth being longitudinally spaced at a distance from saidfirst plurality of teeth, locking means for locking said member in aposition for engagement of one of said first and second pluralities ofteeth with said driven gear, whereby the positioning of said gear forengagement with said driven gear determines the rate at which said motordrives said means for controlling timing operations of said dryer.

13. In a dryer according to claim 12, comprising a first shaft carryingsaid cylindrical member, a second shaft extending parallel to said firstshaft and carrying said driven gear; and wherein said locking meanscomprises a plurality of resilient locking tabs carried by one of saidshafts.

14. In a dryer according to claim 12, comprising a shaft carrying saidcylindrical member, said locking means including a plurality ofresilient tabs extending from said shaft.

15. In a dryer according to claim 14, wherein said plurality ofresilient tabs are divided into two groups, the tabs of a first of saidgroups extending at an acute angle from the surface of and directedtoward one end of said shaft and the tabs of the second group extendingat an acute angle from the surface of and directed toward the other endof said shaft, said cylindrical member being axially movable andreleasably locked between a tab of the first group and a tab of thesecond group.

1. In a timer apparatus of the type wherein a control mechanism iscoupled to be driven by a motor via a gear train including first andsecond meshed gears, the improvement therein of means for varying thegear ratio of said first and second gears to vary the rate at which saidmotor drives said control mechanism, wherein: said first gear includingat least two sections at positions along its axis of rotation, eachsection including a different number of teeth and the teeth of eachsection providing the same mean diameter for said first gear as theteeth in each other section; and locking means for selectively andreleasably locking one of said gears at positions along its axis ofrotation to selectively mesh the teeth of said first gear with the teethof said second gear at different gear ratios.
 2. The improvement intimer apparatus, as set forth in claim 1, wherein said first gear ismounted for rotation on a supporting shaft and said locking meansincludes a plurality of resilient tabs spaced along and extending fromsaid supporting shaft for engaging a face of said first gear when suchface is positioned adjacent thereto.
 3. The improvement in timerapparatus, as set forth in claim 2, wherein said shaft and said tabs areformed as a unitary structure.
 4. The improvement in timer apparatus, asset forth in claim 2, wherein said tabs extend at an acute angle withrespect to the surface of said supporting shaft.
 5. The improvement intimer apparatus, as set forth in claim 4, wherein a first group of saidtabs are directed toward one end of said supporting shaft and a secondgroup of said tabs are directed toward the other end of said supportingshaft so that said first gear may be locked between a tab of said firstgroup and a tab of said second group.
 6. Timer apparatus comprising: amotor; a first shaft connected to and rotated by said motor; a firstgear carried on said first shaft for rotation therewith, said first gearincluding sections axially thereof having different numbers of teeth,said first gear having the same mean tooth diameter at all saidsections; a second shaft mounted for rotation; a control mechanismconnected to said second shaft and operated by the rotation thereof toperform at least one control operation; a second gear having teethengaged with teeth of said first gear and carried on said second shaftfor rotating said second shaft, one of said gears fixed to itsrespective shaft and the other of said gears being axially movable alongits respective shaft; and locking means for locking said axially movablegear at a selected position on its respective shaft for selecting thegear ratio between said first and second gears and the rate of operationof said control mechanism.
 7. The apparatus according to claim 6,wherein said locking means includes spaced, resilient tabs extendingfrom the shaft which cArries the axially movable gear.
 8. The apparatusaccording to claim 7, wherein said tabs and said shaft which carries theaxially movable gear are constructed as a single unitary structure. 9.The apparatus according to claim 7, wherein said tabs extend at an acuteangle with respect to the surface of the shaft which carries the axiallymovable gear.
 10. The apparatus according to claim 7, wherein a firstgroup of said tabs extend at an acute angle from the surface of and aredirected toward one end of the shaft which carries the axially movablegear, a second group of said tabs extend at an acute angle from thesurface of and are directed toward the other end of the shaft whichsupports the axially movable gear, and the axially movable gear may bepositioned and releasably locked between a tab of said first group and atab of said second group.
 11. For use in a coin-operated laundryappliance of the type having a rotatable clothes receptacle, means fortreating clothes within the receptacle and a coin-operated timingdevice, said timing device comprising: a rotatable shaft; means operableupon the insertion of coins of a predetermined denomination to rotatesaid shaft in a first direction; a motor operable to rotate said shaftin the opposite direction; means coupled to said shaft for controllingthe operation of said means for treating clothes; a gear train driven bysaid motor and connected to said shaft and including a first gear havinga plurality of gear sections disposed along its longitudinal axis, eachof said sections including different numbers of teeth and all sectionshaving the same mean tooth diameter, a second gear having teethengageable with the teeth of said first gear, and means for providingrelative longitudinal movement between said two gears and releasably andselectively locking said two gears with respect to said longitudinalmovement to provide a selected gear ratio therebetween.
 12. In a dryerhaving a coin-operated control mechanism, said mechanism having a motorand means including a driven gear driven by said motor for controllingtiming operations of said dryer, an adjustable gear driven by said motorfor varying the rate at which said motor drives said means forcontrolling the timing operations of said dryer, said adjustable gearcomprising: an essentially cylindrical member, a first plurality ofteeth circumferentially protruding from said member, a second pluralityof teeth circumferentially protruding from said member, said secondplurality of teeth being longitudinally spaced at a distance from saidfirst plurality of teeth, locking means for locking said member in aposition for engagement of one of said first and second pluralities ofteeth with said driven gear, whereby the positioning of said gear forengagement with said driven gear determines the rate at which said motordrives said means for controlling timing operations of said dryer. 13.In a dryer according to claim 12, comprising a first shaft carrying saidcylindrical member, a second shaft extending parallel to said firstshaft and carrying said driven gear; and wherein said locking meanscomprises a plurality of resilient locking tabs carried by one of saidshafts.
 14. In a dryer according to claim 12, comprising a shaftcarrying said cylindrical member, said locking means including aplurality of resilient tabs extending from said shaft.
 15. In a dryeraccording to claim 14, wherein said plurality of resilient tabs aredivided into two groups, the tabs of a first of said groups extending atan acute angle from the surface of and directed toward one end of saidshaft and the tabs of the second group extending at an acute angle fromthe surface of and directed toward the other end of said shaft, saidcylindrical member being axially movable and releasably locked between atab of the first group and a tab of the second group.